/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard;

import java.util.List;

import proguard.classfile.ClassPool;
import proguard.classfile.LibraryClass;
import proguard.classfile.ProgramClass;
import proguard.classfile.util.ClassUtil;
import proguard.classfile.util.WarningPrinter;
import proguard.classfile.visitor.ClassCounter;
import proguard.classfile.visitor.ClassVisitor;

/**
 * This class checks whether some keep rules only keep library classes, no program classes. That is strange, because
 * library classes never need to be kept explicitly.
 *
 * @author Eric Lafortune
 */
public class LibraryKeepChecker implements ClassVisitor {
    private final ClassPool programClassPool;
    private final ClassPool libraryClassPool;
    private final WarningPrinter notePrinter;

    // Some fields acting as parameters for the class visitor.
    private String keepName;

    /**
     * Creates a new DescriptorKeepChecker.
     */
    public LibraryKeepChecker(ClassPool programClassPool, ClassPool libraryClassPool, WarningPrinter notePrinter) {
        this.programClassPool = programClassPool;
        this.libraryClassPool = libraryClassPool;
        this.notePrinter = notePrinter;
    }

    /**
     * Checks the classes mentioned in the given keep specifications, printing notes if necessary.
     */
    public void checkClassSpecifications(List keepSpecifications) {
        if (keepSpecifications != null) {
            // Go over all individual keep specifications.
            for (int index = 0; index < keepSpecifications.size(); index++) {
                KeepClassSpecification keepClassSpecification = (KeepClassSpecification)keepSpecifications.get(index);

                // Is the keep specification more specific than a general
                // wildcard?
                keepName = keepClassSpecification.className;
                if (keepName != null) {
                    KeepClassSpecificationVisitorFactory visitorFactory =
                        new KeepClassSpecificationVisitorFactory(true, true, true);

                    // Doesn't the specification match any program classes?
                    ClassCounter programClassCounter = new ClassCounter();

                    programClassPool.accept(visitorFactory.createClassPoolVisitor(keepClassSpecification,
                        programClassCounter, null, null, null));

                    if (programClassCounter.getCount() == 0) {
                        // Print out notes about any matched library classes.
                        libraryClassPool.accept(
                            visitorFactory.createClassPoolVisitor(keepClassSpecification, this, null, null, null));
                    }
                }
            }
        }
    }

    // Implementations for ClassVisitor.

    public void visitProgramClass(ProgramClass programClass) {}

    public void visitLibraryClass(LibraryClass libraryClass) {
        String className = libraryClass.getName();
        notePrinter.print(className,
            "Note: the configuration explicitly specifies '" + ClassUtil.externalClassName(keepName)
                + "' to keep library class '" + ClassUtil.externalClassName(className) + "'");
    }
}
